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View Full Version : I Just Placed an Ad Looking For Ammo



BigMacky
02-23-2008, 08:18 PM
Here's a link to it ....

http://www.benchrest.com/cgi-bin/classifieds/classifieds.cgi?db=ffiammo&website=&language=&session_key=47c0b6297b39c2c8&search_and_display_db_button=on&db_id=389&results_format=long&query=retrieval&exact_match=on

Let me know .... Thanks .... Fred

Douglas
02-24-2008, 06:57 AM
Fred, just curious, why do you want the specific year? I know why you want the ammo, I have just the opposite years I plan on trying. I have 2007 at 1080 and 2006 at 1040. Thanks, Douglas

BigMacky
02-24-2008, 10:07 AM
Douglas,

Yesterday morning I did a bunch of shooting over a chronograph. I had around 10 differents lots with the 1006 Year #, 20 or so lots with the 1007 Year #, and maybe 4 or 5 lots with a 1005 Year # .....

I had suspected some descrepencies in the velocity listed on the box (no not the usual differences due to barrel length, etc) but what I had thought to be huge differences year by year.

I had the chronograph set about 30 feet from the muzzle and I had the console close enough that I was able to read shot by shot what the velocity of each shot was. I shot maybe 3 or 4 shots from each box.

This testing was with a 25" Benchmark 2 Groove Straight Taper Barrel

Here's what I found ....

1005 Year # .... the actual velocity measured was on the average 6-11 fps slower than the number on the box.

1006 Year # .... the actual velocity measured was on the average 3-8 fps slower than the number on the box.

1007 Year # .... the actual velocity measured was on the average 17-22 fps slower than the number on the box.

So what does that mean .... well the 1040 fps 2006 ammo would shoot around 1032-1037 fps in my rifle .... the 1080 fps 2007 ammo would shoot around 1058-1063 fps in my rifle.

In your case, you'll be comparing 1035 fps average ammo to
1060 fps average ammo ... a difference of 25 fps (not as much as the 40 fps that you thought) harder to read a difference in vertical.

The ammo that I was hoping to use didn't fair as well .... because of the difference in the variance in different years mine would have only been maybe 10 fps apart. Not Good for what I'm trying to do

So that's the scoop .... like I said, we didn't have enough to make us crazy.

Fred

Douglas
02-24-2008, 03:26 PM
So if I understand correctly, you actually want a difference greater than 40fps? If I did the calc right you'd have a difference of 55fps; 1040fps 2007 = 1020, 1080fps 2006 = 1075.

Thanks, (now I need a chronograph it never ends) Douglas

BigMacky
02-24-2008, 03:48 PM
Doesn't have to be 40 fps ..... some have gone with 25-30 .... IMHO the bigger the spread the easier it is to see the vertical spread .... you said you had 2007 stuff that is labelled 1080 ... that was shooting around 1058-1063 .... the 2006 stuff that you have labelled 1040 was shooting around 1032-1037 .... an average difference of 25 fps

Fred

Al Hadfield
02-24-2008, 05:21 PM
Hi Fred,

Pardon me for butting in, but I’m curious...why do you set the chronograph screens at 30 feet?

Al

BigMacky
02-24-2008, 06:24 PM
Hi Al,

Not sure if you meant how come that far or how come that close.

That's as far as I can place it in my basement and I wanted to get it as far from the muzzle as possible to avoid picking up any muzzle blast.

Fred

Al Hadfield
02-24-2008, 07:23 PM
Hi Al,

Not sure if you meant how come that far or how come that close.

Fred


I was thinking why that far. I’m no expert but comparing Eley’s “muzzle velocity” to your readings taken at 30 feet would introduce an error. Seems you would tend to get a slower reading that could, to some extent, account for the slower readings you are seeing. Don’t get me wrong, Eley’s numbers are often quite different than “real world” results.

Think Spring! Al :)

BigMacky
02-24-2008, 08:10 PM
Hey Al,

The relative difference is what's important ..... not how far off from what's on the label ..... the fact the 1007 is close to 20 fps off while 1006 is more like 5 fps off kinda makes the velocity on the box from year to year useless.

Fred

tim
02-24-2008, 08:47 PM
I don't want to burst your bubble here but since that speed has always been good only in their test guns, has it not pretty much always been useless?
It's always been usefull only in some very basic starting point in testing, no?

BigMacky
02-25-2008, 05:22 AM
Hey Tim,

Not bursting my bubble :) ..... I'm not trying to reason why the velocity on the Box does not match the velocity I am seeing with the chronograph.

I am concerned though that one year the difference on the label and what I'm seeing on the chronograph is around 5 fps difference and another year the difference is 20 fps. Kinda makes selection of test lots for the following year a little tough if labelled velocities vs chronographed velocities change that much from year to year.

All I'm doing here is posting what I found ... as the "disclaimer" goes ... Your mileage may vary.

I do know one thing for sure .... shooting over a chronograph to "validate" the accuracy of ammo box labels WILL be part of my routine. For me that will likely be 5 or shots from a few different boxes over the chronograph .... Then there are others that it won't matter to.

I think it will be up to the individual ....

Fred

Douglas
02-25-2008, 09:47 AM
Fred, I guess the bottom line of your little test, as far as I'm concerned, is if I want my desired spread of 40fps, is to use 1040 and 1080 from same year. I understand why you want the years you indicated, you want a greater spread than 40fps. Keep up the good work, very enlightening. Thanks, Douglas

BigMacky
02-25-2008, 09:51 AM
Hi Douglas,

Yup .... if you get ammo from the same year I think the chance of the spread being accurate is better ... as far as a 40 fps spread is concerned one may not really need that much. I'm only thinking that the wider the spead the more obvious the vertical dispersion will be and the easier it will be to see the improvements.

Looks like this Saturday and Sunday is gonna be TESTING Days ... we'll see how things go then.

Fred

tim
02-25-2008, 11:40 PM
Far be it for me to offer any advice but you might ultimately end up finding out exactly why lots of these indoor .22 ranges have some serious ventilation. Hint.... make sure you keep your health insurance premiums paid up.

BigMacky
02-26-2008, 12:22 AM
Far be it for me to offer any advice but you might ultimately end up finding out exactly why lots of these indoor .22 ranges have some serious ventilation. Hint.... make sure you keep your health insurance premiums paid up.

Windows and garage door cracked open, and Exhaust fan running

BTW ... this w/e isn't a basement testing day

Fred

gerald
02-26-2008, 07:40 AM
I was told Eley shoots through a donut baffel with the chronoguaph set closer to the muzzle.

langenc
02-26-2008, 01:29 PM
I dont do chronographing but always thought bullets that were more the same/batch were better that something to do with actual velocity vs box velocity??

tim
02-26-2008, 05:45 PM
Fred, seriously, this is not safe, even a little bit. I mean hell, your free and over 21 but Goggle up the OSHA paper on this shooting induced airborne lead stuff, you're srewing with big health risk here.

BigMacky
02-26-2008, 08:11 PM
Hey Tim,

I'll look for those articles and see what they say. I do try to ventilate whenever I shoot .... and if I'm going to be doing any amount of shooting I wear a respirator ... it's the one that I use when I do woodworking. I unscrew the canister towards the stock and cover to hole with duct tape.

This is the one ..... http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100074692

Thanks for the info ..... Fred